1. Field of the Invention
The invention relates to an externally held, adjustable spreader for tubular materials present in a flat state. The spreader includes at least two spreading and guiding units which are laterally juxtaposed in the interior of the tubular material. Each unit is provided with at least one endless transporting belt which extends over part of its circumference along the outer guide face of the associated guide unit and is in releasable engagement with feed rollers disposed on the exterior of the tubular material to pass through.
2. Description of the Background
German Pat. No. 2,939,085 and U.S. Pat. Nos. 2,553,074 and 3,479,706 disclose spreaders disposed in the interior of a tubular material in the form of a flat frame that can be adjusted in width by means of a telescoping tube and in which the outer ends of the telescoping tubes are connected with the frame by way of head members.
However, these kwown spreaders all have the serious drawback that they are adjustable in width by way of the telescoping tubes only within relatively narrow limits. Adjustment of the spreader while tubular material is passing through, for example successive, connected tubular materials of different widths, is not possible. If the width of the tubular material passing through changes, its feed must be interrupted, the materials having the different widths must be separated from one another and the width of the spreader must be adjusted accordingly or, if its adjustment range is insufficient, the speader must be exchanged. This constitutes a very undesirable and cumbersome interruption of the work process which is desired to be as continuous as possible.